Over the past decade, public health experts have become increasingly alarmed about the spread of the HIV/AIDS among people with severe mental disorders. Most of the research in this area, however, has focused either on describing mental illness clients' risk behavior or on establishing the efficacy of specialized intervention protocols. Very little attention has been given to examining what mental health professionals are doing in their everyday practice to respond to their clients' HIV-related needs. This study examines the HIV-related mental health services provided by clinicians to a random sample of people with serious mental disorders in community-based care. The specific aims of this pilot study are to: 1) measure and document the range and intensity of HIV-related mental health services provided by professionals in community support programs for people with serious mental illness; 2) describe the clients who are receiving HIV-related mental health services and identify clinical and organizational factors which affect clinicians' knowledge of clients' HIV/AIDS needs and the frequency and intensity that they provide HIV-related mental health services; and, 3) examine the impact of HIV-related mental health services on clients' HIV risk behavior, knowledge and beliefs about HIV/AIDS sexual risk networks, and sexual decision-making. This project is based on a cross-sectional survey of 300 randomly selected clients and selected members of their treatment teams in three community support programs in Indiana. Clients are asked to describe their risk behavior using standardized risk behavior inventories. They are also questioned about their perceptions of the HIV-related services provided by clinicians. Staff are asked to assess their clients' HIV risk and the organizational support for providing such services. Services data are culled from clinic charts and administrative computer data sources. This study will fill an important gap and provide critical scientific data for planning future effectiveness trials of specific HIV-related mental health services. The project will also offer important practical insights on the services-related barriers which public health leaders will need to address in future efforts to implement wide-spread HIV prevention programs for mental illness clients. Ultimately, the potential preventive role community support programs might play in slowing the spread of HIV in this population will depend on a better scientific understanding of the service-related conditions which affect the provision and effectiveness of HIV-related mental health services.